Carburetor



G. A. EYNON July 21, 1931.

CA'RBURETOR um o SA .Q

N .ma

INVEN TOR.

-A TTORNEY.

G. A. EYNON July 21, 1931.

CARBURETOR Filed Jan. ll, 1930 5 Sheets-Sheet 2 v IN VEN TOR.

. ATTORNEY.

G.V A. EYNON July 21, 1931.

CARBURETOH Filed Jan. l1, 1950 3 Sheets-Sheet 5 INVENTOR.

A TTORNEY.

Patented July 21, 1931- GEORGE A. EYNON, O F PARMA, OHIO CABBUBETOB Application med January 11, 1930. ASerial No. 420,026.v

This invention relates to improvements in carburetors and has for -its principal object to provide a carburetor which will give at ordinary driving speeds a maximum fuel 15 economy and at full throttle willl .give a maximum of power. Y A further object. is to provide such a carburetor with a more elicient idling arrangement whereby the fuel mixture may be adjusted vafter being mixed and may be admitted on the engine side of the throttle. @ther and more specific objects will appear as the description proceeds.

Referring to the accompanying drawings, Fig. 1 is a schematic vertical section of my improved carburetor; Fig. 2 is a fragmentary section on line 2-2 of Fig. 1; Fig. 3 is a fragmentary section on line 3 3 of Fig. 1; Fig. 4 is a detail section of the lower end of the adjusting needle 21; Fig. 5 is a fragmentary section on line 5-5 of Fig. 1; Fig.

6 is a fra entary section on line 6,-6 of Fig. 1; Fig. is afr'agmentary vertical section taken at right anglesto the showing in Fig. 1; and Fig. 8 is a vertical section on line 8-8 of Fig. 7.

My improved carburetor, as best shown in Fig. 1, includes the conventional floatchamber F and air inlet A of usual construction, a mixing chamber M including the conventional venturi 44, a throttle valve 37 and a conduit C continuous with the mixing chamber M and adapted to be connected to the intake manifold of an internal combustion engine by any suitable means (not shown). r.lhe oat chamber F is provided with an iniet 12 for 'uel which is controlled by a needle valve 14seating in the bore 418, held in position by braciet 15 secured by screws 16 and controlled by the float 11 which is pivoted at 17 by means of an arm20 attached at 19 and providedwith a boss 18 adapted to contact with the needle 14.

The air inlet A comprises the usual tubujournaled in the tubular portion by means of a shaft 46 containing a slot through which the Vbuttery valve 47 extends and in which the same is secured and controlled bya lever 5@ 46.secured in iixed relation to said shaft 46.

lar portion having a butterfly valve 47 v float chamber F and has a fixed dimension determined by the restricting means 49. rlhe tube51 communicates also with the ioat chamber through the opening 22 but this opening is adjustably controlled by the needle 21 provided with a threaded portion 23 which extends through the upper Wall of the float chamber and is provided with a knurled head 24. The tube 51 communicates with the chamber S, the chamber into which fuel from the mixing chamber is directed through the bore 22. Also communicating with the chamber S is apassage 26 having an enlarged lower end forming a well and a smaller passage 26a continuous with said well and communicating through the throttle rod 40 with the atmosphere in a manner to be hereinafter described. f

IThe well forming a part ofthe passage 26 should be considerably larger than the portion 26al thereof and ma be of any deslred shape, that shown, circu ar` or any other desired. The construction of the needle 21 is shown in detail in Fig. 4 and includes a bore 21a passing radially through the needle, a large bore 21 extending longitudinally and connected with the bore 21a by a restricted bore 21, whereby the fuel supply from the float chamber into the chamber S is never entirely cut olf. y

rlhe idling mechanism consists of a well 54 communicating by an opening 27 with the oat, chamber through a restrictlngplug 27a. rlhis Well 54 is in unrestricted communica-v tion with the atmosphere throu h an opening 54a at the upper end. Exten ing into the well 54 is a tube 53 communicatin with a mixing chamber 29 and provided with a restrictingplug 48. Above the restricting plug 48 is an openin 34 which communicate'srwith the atmosp ere as best shown in Fig. 3. In the mixing chamber 29 is an opening 28 which vcommunicates with the at- 'mosphere as best shown inA Fig. 6. The mixing chamber 29 communicates with the conduit C through two p'orts 35 and 36. When the throttle is closed, the port 36 is rendered substantially or entirely inoperative as indicated in Fig. 1. This port 36 is employed only when the throttle is opened somewhat andthe port is relied upon for idling.' A needle 3 0 is threaded through the casting as shown at `32 and provided with a knurled head 31 by means Vof which the saine may be rotated to adjust the effective size of the opening 35. A l 4 The passage 26 extends tothe journal 38 in which the shaft is rotatable and communicates with the bore therein in which said shaft rotates. A second bore 39 in said journal also communicates with the bore in which the shaft 40 is journaled and a notch 40a is provided in the shaft 40 and connects the passages 26 and 39 when the throttle is closed and until the same has been opened to about 35, corresponding substantially to halfthrottle. It will be evident that after the throttle is open, the air which passes through 39 into 26 will be gradually reduced.

Operation Assuming the throttle in the position shown in the drawings, the carburetor will be in idling position. The suction produced by the en 'ne will communicate with the port 35 an cause fuel to flow from the ioat chamber F through the opening 27 into the Well 54, into the tube 53 and through the restricted passage 48. At the same time, air will flow into theV opening 34 and mix with the fuel coming through the passage 48. This mixture will How into the mixing chamber 29 and there be further mixed by the introducti'on of air through the passage 28. These passages are proportioned so as to be of such size that a-.desirable mixture is obtained. f The amount of air fuel mixture admitted through the ort 35 may be adjusted by `means of the needle 30. The well 54 wili at the time of starting the motor have a fuel level as high as that in the iioat chamber and this extra supply of fuel provides for the demands of starting.

When the throttle is opened, the port 36 will be uncovered and suction from the motor will be transmitted to the mixingchamber 29 and will suddenly increase the suction through the tube 53 to draw more fuel from the idling supply andthe reserve fuel in the well 54 may be relied upon'to supply the fuel demand caused thereby. At the same time, the engine suction communicates with v the tube 50 and causes a jet of fuel to How from the float chamber into the mixing chamber through the restriction 49. Thus through the tube 50 a constant supply of fuel proportionate to the engine suction is VS by fuel entering through the port 22 and air entering through the port 26 communicating therewith. It will be obvious that before the throttle is opened, the fuel level in the passage 26 will be at the level in the float chamber and that consequently a rich mixture will be supplied for starting by rea` son of the, fuel inthe well being drawn through the port 27 and opening 25 into the tube 5l. As soon as this level is brought down so that the well is empty, there will be air entering through the bore 26 and fuel through the port 22 which will be mixed in the chamber S and drawn through the restrition 25 into the tube 5l and thus delivered to the mixing chamber M. After the throttle is 'substantially half open, that is, has been opened through about 350, the air supplied to the passage 26 will have been cut off by the passing of the notch 40 in the shaft' 40 out of registe'rwith the port 39 and as a result only pure fuel without air will be delivered through the tube 5l to the mixing chamber. Consequently, it will be seen that up to approximately half throttle, that is, in the ordinary driving ranges, a main j et of fuel will be supplied through the tube 50 and a mixture of fuel and air will be supplied through the tube 5l but that from approximately half throttle to full throttle, fuel only will be delivered through the tube 51 which will result in a richer mixture and consequently increased power. The feature of cutting off the supply of air through port 39 at approximately half throttle results in materially increased power for rapid acceleration and fast driving. The presence of the supply of air through port 39 at normal driving positions" gives risc to the maximum fuel economy.

While I have shown openings 28 and 28x1 communicating between the mixing chamber 29 and the atmosphere and said mixing chamber and the chamber M respectively, it is to be understood that may employ either or both of these openings as desired. If both are used the sizes will be proportionally diminished. If only one is used the other will be closed by means of a plug or omitted entirely. In general l prefer to employ the opening 28 since by so doing l obviate an undesirable sound produced by the rushing of air through the-opening.

It will thus be seen that I have provided a carburetor having an eliicient idling mechanism, and capable of delivering at ordinary driving positions of the throttle a maximum fuel economy and at positions approaching full throttle a maximum power.

While lf have shown one embodiment of Lsiaeeo my invention, wish it understood that the same is merely illustrative and schematic and that I am limited only in accordance with the scope of the appended claims.

Having thus described my invention, what l claim is':

l. A carburetor including a mixing cham- "ber, a throttle, an air inlet and-a constant level fuel chamber, a main fuel supply nozzle communicating between said `constant level fuell chamber and said mixing chamber, an auxiliary fuel supply vnozzle communicating with said mixing chamber adjacent said main nozzle, a shaft carrying and controlling said throttle, a notch in said shaft, a passage in said carburetor body to atmosphere intersected by said shaft, a larger passage communicating with said constant level fuel chamber, said iirst passage and, through a restriction, with said auxiliary fuel supply pipe, said notch being so formed as to open the passage at closed throttle, gradually restrict said passage as said throttle is opened and to substantially close said passage through at least the -last quarter of its throw;

2. A. carburetor having a g chamber, an air inlet and a'constant level fuel chamber, a shaft journaled in .the body of said carburetor, a throttle carried by said shaft, a main nozzle delivering into said mixing chamber and communicating only with said mixing chamber and said constant level fuel chamber, an auxiliary nozzle delivering into said mixing chamber and connected to an auxiliary fuel chamber, said auxf iliary fuel chamber also communicating with said constant level fuel chamber, a passage intersectedby said shaft and connected between said auxiliary fuel chamber and outer atmosphere, said shaft embodying means for opening said passage at closed throttle, progressively closing said passage as the throttle is opened at such a rate that same is substantially closed between three fourths and full throttle.

ln testimony whereof, hereunto afix my signature.

GEORGE A. EYNUN. 

